Electrical attachment-plug.



PATENTED SEPT. 12, 1905.

B E SALISBURY ELECTRICAL ATTACHMENT PLUG.

APPLICATION PILED JULY 20,1904.

INVENT OR WITNESSES:

UNITED STATES PATENT OFFICE.

BERT E. SALISBURY, OF SYRACUSE, NEW YORK, ASSIGNOR TO PASS & SEYMOUR, INCORPORATED, OF SOLVAY, NEW YORK.

ELECTRICAL ATTACHMENT-PLUG.

Specification of Letters Patent.

Patented Sept. 12, 1905.

To (1/7] whom it may concern:

Be it known that I, BERT E. SALISBURY, a citizen of the United States, residing at Syracuse, in the county of Onondaga and State of New York, have invented certain new and useful Improvements in Electrical Attachment-Plugs; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to an attachment-plug adapted to be used with ordinary sockets for making connections for electric lighting; and it consists,essentially,in a plug member carrying the wire-terminals and the contact-terminals, which engage and make contact with the corresponding terminals of the socket,and of a brass cap covering and protecting the top of the plug and provided with insulating fiber parts to guard the wires from contact with the brass cap.

This attachment-plug is strong, simple, and economical in construction and of a neat appearance and has certain features which are great practical improvements.

The invention will be understood by reference to the drawings herewith, in which the reference letters and numerals of the specification indicate the corresponding parts in all the figures.

Figures I and II are vertical sections at right angles to each other. Fig. III is a top plan of the plug member with the cap removed. Fig. IV is an isometric view of the fiber bushing. Fig.V is a section of a slightlymodified brass cap.

In the figures, A indicates the portion made of porcelain or other suitable insulating material and having a shank 1,vertically grooved on opposite sides at 2 and 3, an enlarged substantially circular top 4:, an annular flange 6 to separate the threaded terminal from the cap, an upper margin 7 to fit within the fiber lining of the cap, flattened sides 8 and holes 9 for the cap-screws, and a depression within the upper margin divided by wall 11 to insure separation of the wireterminals 15 16, arranged each in aseparate cavity. IVire-terminal 15 is secured in position by screw 18, which carries at the outer end washer 19 fora central contact. The threaded brassor copper shell 21, forming the outer contact, is secured in position by ear or lug 22, fixed in its upper edge and fitting within groove 2, with which engages screw 23, also securing in place wire-terminal 16.

2O 20 are binding-screws in the respective wire-terminals for the wires.

If desired, vertical groove 3 may be provided and filled, more or less, with plastic insulating material to engage with the threaded shell 21 and insure its being maintained firmly in position.

The brass cap B is provided with a flange 25, fitting the plug-top and carrying screws 26 to engage with attachment-holes 9. The cap is preferably grooved at 30, into which groove is sprung the fiber cap 32, which fits around the margin 7, cooperating therewith to prevent short-circuiting of the wires on the cap. Such accidental contact is further guarded against by the fiber bushing 35, fitted into the wire-hole and retained in position by shoulder 36, which not only protects the wires, but is more economical than the ordinary brass bushing heretofore in common use. As most of the porcelain parts are covered by metallic parts, only the tip of the shank and the lower portion of the porcelain top are necessarily glazed. This form of cap, fiber lining, and bushing of fiber or other suitable insulating material and means to secure fiber lining and bushing in position are not limited to be used with a plug, but may be used with sockets or other devices to which these parts are adaptable.

In Fig. V is shown a slightly-modified form, in which the continuous groove 30 is omitted and the lining of fiber or other suitable flexible insulating material retained in position by being sprung over lugs 40, formed in the metallic cap.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. In a device of the character described, a metallic protecting-cap, having an annular flange and formed with a continuous groove adjacent to the top of the flange, and in combination therewith a fiber lining fitted to the cap and having its margin arranged in the groove.

2. A metallic protecting-cap for an electrical device substantially of the character described, havinga central cord-hole and an annular groove, and in combination therewith a bushing of insulating material fitted to the cord-hole, and a lining of flexible insulating material arranged within the cap and with its margin in said groove.

3. An electrical attachment-plug having in combination an insulating plug member formed with a shank, a circular top and a flange around the top, terminals on said top, contacts on said shank, connections between the respective terminals and contacts, a metallic protecting-cap adapted to fit over the top of the plug member against the flange, and means to connect the cap to the plugmember. V

4. An electrical attachment-plug, having in combination a porcelain plug member having a shank, a circular top, a depression in the top, an upwardly-extending margin around the depression, a flange around the lower portion of the top, terminals in the cavity, contacts on the shank, connections between the respective terminals and contacts, and a metallic cap adapted to fit the top of the plug member.

5. An electrical attachment-plug having in combination a porcelain plug member having a shank, a circular top, an outwardly-extending flange around the lower edge of the top, a smooth annular portion above the flange provided with screw-holes, a depression in the upper surface of the top, an upwardly-extending margin around the depression, a cross-wall dividing the depression, metallic wire-terminals arranged respectively on opposite sides of the cross-wall, lamp-contacts on the shank, connections between the respective lamp-contacts and terminals, a metallic cap fitting the top of the plug, and screws in the sides of the cap to engage with the screw-holes.

6. An electrical attachment-plug having in combination a porcelain plug member having a shank, a circular top, an outwardly-extendinguflange around the lower edge of the top, a smooth annular portion above the flange provided with screw-holes, a depression in the upper surface of the top, an upwardlyextending margin around the depression, a cross-wall dividing the depression into two cavities; metallic wire-terminals arranged in the respective cavities, a washer on the end of the shank, a securing-screw connecting the washer with one of the wire terminals, a threaded metallic shell arranged around the shank, a securing-screw connecting said shell to the second wire-terminal; a metallic cap fitting over the top of the plug, said cap having an annular margin, an upper dome and a central cord hole in the dome, screws arranged in the side of the cap to engage with the screw-holes; a fiber bushing fitted to extend out through said cord-hole and having a flange arranged to engage with the inner surface of the cap and a fiber lining arranged within the cap to cover the bushing and having its edge arranged in agroove in the cap, said lining fitting around the upper margin of the plug.

7. An electrical attachment-plug having in combination a porcelain plug member having a shank, a circular top, grooves in the sides of the shank, an outwardly-extending flange around the lower edge of the top, a smooth annular portion above the flange provided with screw-holes, a depression in the upper surface of the top, an upwardly-extending margin around the depression, a cross-wall dividing the depression into two cavities, metallic wire terminals arranged in the respective cavities, a washer on the end of the shank, a

securing-screw connecting the washer with I one of the wire-terminals, athreaded metallic shell around the shank, an ear connected to said shell and arranged in one of the grooves, a securing-screw engaging with said ear and connecting said shell to the second'wire-terminal, plastic material in the second groove to engage with the threaded shell, a metallic cap fitting over the top of the plug, said cap having an annular margin, an upper dome and a central cord-hole in the dome, screws arranged in the side of the cap to engage with the screw-holes, a fiber bushing fitted to said cord-hole and having a flange arranged within the cap, and a fiber lining arranged within the cap to cover the bushing and having its edge engaging with a groove in the cap formed where the margin joins the dome, said lining fitting around the upper margin of the plug.

8. An electrical attachment-plug, having in combination a plug member of insulating material formed with a shank, a circular top, a flange around the top and an upwardly-extending margin above the flange and around the top, metallic terminals on the upper surface of the top within the margin, metallic contacts on the shank, metallic connections between the terminals and the contacts respectively, a metallic protecting-cap adapted to fit over the top of the plug member and to extend down adjacent to the flange, a lining of insulating material within the cap, and means to secure the cap to the plug member.

9. A metallic protecting-cap for an electrical device substantially of the character described, having a domed upper portion and a cord-hole centrally arranged in said portion, and in combination therewith a bushing of insulating material having a cylindrical portion and a shoulder on its inner end, said cylindrical portion being arranged to extend outwardly through the cord-hole of the cap, and the shoulder, to engage with the inner surface of the cap.

10. A metallic protecting-cap for an electrical device substantially of the character described, having a central cord-hole in its upper portion, the cord-hole being surrounded by a thin metal edge and in combination therewith a removable insulating fiber bushing having a cylindrical portion and a shoulder on its inner end, said cylindrical portion being adapted to be inserted in the cord-hole, ex tending outwardly therethrough and engaging with said thin edge, and the shoulder adapted to engage with the inner surface of the cap.

11. In an electrical attachment-plug, the combination with the porcelain plug member formed of a single piece, metallic contacts on the lower portion of the plug member, metallic wire-terminals on the upper end of the plug member, connections between the respective terminals and the respective contacts, an integral margin on the upper end of the plug, surrounding said terminals, said plug member being provided with screw-holes in its upper portion below the margin, a metallic cap fitting the upper portion of the plug member, an insulating-lining within the cap, said lining being adapted to lit around said margin, and screws carried in the cap edge to engage with said holes.

12. In an electrical device substantially of the character described, a metallic cap having a dome and a grooved portion between the lower margin and the dome, and in combination therewith a lining of insulating material arranged within the cap and having its margin arranged in the grooved portion, said cap and lining being formed with central registering cord-holes.

In testimony whereof I aflix my signature in presence of two witnesses.

BERT E. SALISBURY.

WVitnesses:

L. JOHN BERGM N, J. WV. BROOKS. 

